Eden Riegel

The Young and the Restless star Eden Riegel will guest-star on Castle this season, TVGuide.com has learned exclusively.

The Daytime Emmy award-winner, 29, will play Rachel Goldstein, the distraught sister of a man killed by an antique pistol in the fourth episode of the season.

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Before joining the cast of Young and the Restless, Riegel won a Daytime Emmy in 2005 for playing Erica Kane's (Susan Lucci) lesbian daughter Bianca on All My Children.

The third season of Castle premieres on Monday, Sept. 20 at 10/9c.